1. Field of the Invention
Embodiments of the present invention generally relate to virtualization technologies, and, more particularly to a method and apparatus for resolving volume identifiers associated with a virtual machine.
2. Description of the Related Art
Various virtualization technologies are widely used across numerous organizations to efficiently use computer resources. Virtualization refers to a level of abstraction that represents several physical resources as a single resource and vice versa. A “virtualized” device breaks the traditional interdependence between physical and logical devices. In many computer systems for large and small organizations, best practices for the various virtualization technologies are being employed.
Window volumes are created on a hard disk by providing parameters to disk creation utilities such as F disk on Windows NT or Disk Druid on Linux. The parameters includes information such as partition type, volume name and volume size. The disks are partitioned for MICROSOFT Windows in accordance with one or more partition tables (e.g., Master Boot Record (MBR), Extended Boot Record (EBR), Globally Unique Identifier Partition Table (GPT) and the like). Each partition comprises one or more volumes (e.g., physical or logical volumes). One or more file system objects within each volume are organized by a file system, such as FAT32 (File Allocation Table with 32-bit cluster numbers) and/or NTFS (New Technology File System).
Currently, applications attempting to directly interpret the file systems of the raw virtual disk drives of a virtual machine are unable to display volume identifiers (e.g., Windows Drives such as C: or D: and the like). Information needed to display the volume identifiers is stored within the partition tables, but such information is insufficient for the applications to clearly identify all volumes. Neither the Master Boot Record nor the Extended Boot Record store the volume letter or volume GUID. The GUID Partition Table does store the volume GUID but not the volume letter. Only the Logical Disk Manager database specifies the drive letters or volume GUIDs. Consequently, the applications which are attempting to directly interpret the file systems within the virtual machine are unable to clearly identify the embedded volumes. Such a limitation fosters a difficulty in understanding the correlation between the raw partitions and actual volume identifiers for application users.
Therefore, there is a need in the art for a method and apparatus for resolving volume identifiers to enable file restoration from a virtual machine image in an efficient and cost effective manner.